The present invention relates generally to the field of cutting instruments for paper, card stock, mylar, plastic sheeting, cardboard, and other thin media. More particularly, the present invention relates to cutting instruments which follow the shape of a template in order to cut a piece of the thin media in the shape of the template. Templates of this kind often have intricate shapes with corners and curves which are difficult to negotiate with a knife or other simple manual cutter. The present invention uses a novel swivel-offset blade and a specially designed guide to more easily and effectively follow the contour of an intricate template thereby making a more accurate replica of the template shape without tearing, excessive under-cutting or template jumping.
Templates are often used to reproduce an object with a specific shape. Current methods include tracing with a pencil or pen and then cutting with scissors or using a straight edge knife such as hobby knife to cut the shape directly from the template. When the reproduced object shape is a simple polygon, the template may simply be a straightedge, which is placed along each edge of the object as it is cut or traced. More complex shapes require a template, which may have multiple curves, circular holes or holes of other shapes, acute angles and other intricate and complex shapes. A straight-bladed knife works well for simple polygonal shapes with straight sides, however cutting complex and intricate shapes with a simple straight blade can require repeated lifting and repositioning of the blade which can often result in cutting the template. Blade repositioning can often lead to template movement, jagged edges and over-cutting where the blade cuts past a corner point. Repositioning can also cause skipping where the cut does not extend to an intended intersection or corner. This leaves skipped spots in the cut, which can rip and damage the media being cut. Often, a person cutting around a detailed template must lift the knife and reverse the cutting direction in order to cleanly and completely cut an inside corner or other complex intersection.
An accurate cut must also follow the template exactly. If a knife blade varies from a direction parallel with the adjacent edge of the template, the knife blade may stray away from the template or cut into the template yielding a product with irregularities that does not reproduce the template shape. In order to accurately and consistently keep the knife blade parallel with the template edge, the knife operator must constantly change the blade direction based on her visual reference to the template. When cutting at high speeds, this can be difficult if not impossible.
Templates are often used for art and craft projects where matting, decorative paper, Mylar, laminating sheets, foil and other media are common. They may also be used with adhesive sheets, leather, upholstery material, cloth and other textiles or plastic products. With a template these media may be repeatedly cut into myriad intricate and identical shapes, so long as the template shape is accurately and consistently followed.
With a visual reference to the cut so important in achieving an accurate cut, some prior art knives with bulky handles are troublesome as they obscure the cut area from the operator""s view. Narrow handles, however, often provide an inadequate grip and may cause blistering or soreness with repeated use.
The present invention relates to a template-following cutter designed to accurately cut a thin medium while following the shape of a template and provide the user with a comfortable grip and a clear view of the cut. Embodiments of the present invention comprise a handle with a swiveling knife mechanism and a template following guide mounted on one end. A transparent handle is provided so that the user can view the cut area through the handle of the cutter thereby providing the user with an unobstructed view. The handle is also shaped with a cross-section that comfortably fits the average hand so that the cutter can be comfortably and easily drawn around templates for sustained periods. The comfortable grip also aids in cutting thicker or tougher materials that require additional force to cut.
In some embodiments of the present invention, the swiveling knife mechanism preferably utilizes a bearing to enhance rotation. The knife mechanism also comprises a knife offset wherein the knife blade is offset from the axis of rotation of the swivel mechanism so as to cause the knife to automatically align itself in the direction being cut parallel to the template being traced. This knife mechanism also comprises a knife blade with a blade angle designed specifically to enhance blade alignment and reduce ripping of the media being cut. The knife mechanism is also made as a removable cartridge so that a dull or damaged blade may be easily replaced and so blades for different mediums may be easily interchanged.
The template following guide comprises a guide shaft mechanism that guides the blade along the edge of the template being traced, and a guide foot mechanism that lifts the template from the medium being cut so as to guide the template to properly contact the guide shaft. The template following guide may be attached directly to the knife mechanism or to the handle. The template following guide is configured such that it minimizes the amount of undercut and maximizes automatic blade alignment.
Consequently, it is an object of preferred embodiments of the present invention to provide a cutter that provides an unobstructed view of the cut area.
It is another object of preferred embodiments of the present invention to provide a cutter with a transparent handle.
It is an additional object of preferred embodiments of the present invention to provide a cutter with a comfortable handle.
It is a further object of preferred embodiments of the present invention to provide a cutter that automatically follows a path that is parallel to the template being traced.
It is yet another object of preferred embodiments of the present invention to provide a cutter with a blade that freely rotates so as to easily align with the cutting direction in order to facilitate clean cutting and to minimize tearing caused by a misaligned blade.
It is a once further object of preferred embodiments of the present invention to provide a cutter with a blade angle and/or curvaturexe2x80x94that minimizes ripping of the media being cut and maximizes smooth template following.
It is another additional object of preferred embodiments of the present invention to provide a cutter with a guide that prevents the cutter from jumping over or cutting the template.
It is yet another additional object of preferred embodiments of the present invention to provide a cutter with a blade and guide combination that allows a medium to be cut directly beneath the template being traced.
It is once further another additional object of preferred embodiments of the present invention to provide a cutter with a blade and guide combination that controls the offset between the blade and the template being traced.